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Searching Google in Firefox causes a download dialog which detected JSon Activity !

It happens several times and interrupts my typing.

I disabled half of my addons that I thought were suspicious. I also upgraded my FF to version 12.0 (current) — no difference.

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How about disabling FlashGot? Or running Firefox in safe mode to disable all plugins temporarily? – Bob Apr 28 '12 at 8:03
Hi, I didn't try safe mode, think it shouldn't appear on that, cause every feature is disabled :D, but I disabled flashgot with no luck – Sypress Apr 28 '12 at 9:17
Try it. Note this is the browser safe mode, not the operating system safe mode. It will help narrow down if it's an addon causing the issue or a browser misconfiguration somewhere. – Bob Apr 28 '12 at 9:32
up vote 4 down vote accepted

This could either be caused by a malfunctioning extension or a browser misconfiguration. The way to find out is to try running the browser in safe mode - note this is not your operating system's safe mode.

If safe mode still exhibits this problem, it's a misconfiguration of how Firefox handles MIME types, or at least this specific one.

Reset all MIME type handlers:

  1. Type about:config into the address bar.
  2. Find the preference and, if it is present, right-click on it and select reset.
  3. Find the preference plugin.disable_full_page_plugin_for_types and, if it is present, right-click on it and select reset.
  4. Open the profile folder. (The profile folder is hidden by default in Windows 7/Vista/XP/2000 and Linux; read this for help finding it). Note: In Firefox 3.6 and above you can open the profile folder from the Firefox menu, via "Help -> Troubleshooting Information".
  5. Completely close your Mozilla browser.
  6. Delete (or rename) the file mimeTypes.rdf. Caution: There is also a mimeTypes.rdf file in the program folder. Do not delete it by mistake.

More information (source)

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Thanks Bob, I myself guessed it should be related to browser config or addons as you said, you give a comprehensive info on this and this is appreciated, I will try playing with that considering your provided information – Sypress Apr 28 '12 at 9:52

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